Valveless percussive tool.



L. G. BAYLES. VALVELESS PERCUSSIVE'TOOL.

APPLIUATION FILED N0.V.13,1912.

Patented July 7, 1914.

FIGI

FIG-.4-

IN VE N TOR WITNESSES:

B Y M .4 TTOR/VEY ED STA'rns OFFICE. I

. I LEWIS CON'JDICT BAYLES, 0F EASTON, PENNSYLVANIA, ASSIGNOR TO INQHRSOLL-LRAND COMPANY, 01: J'ERgEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

vnnvannss rnnoussrvn TOOL.

Specification of Letters Patent.

Patented July 7, 1914.

Application filed. November 13,1812. Serial No. 731,081.

To all whom it may concern Be it known that I, Lew s G. Barman, a citizen of the United States; residing at Easton, in the county of Northampton and State of Pennsylvania, have invented a certain new and useful Improvement in Valveless Percussive Tools, of'which the followin is aspecification.

Ihis invention relates to fluid operated percussive tools and more particularly to the admission of the motive fluid producing the reciprocations of the piston is controlled by the movement of the piston itself.

The object of the present invention is to construct a tool which combines high elliciency with a low fluid consumption and at the same time is of simple and strong construction, a feature of the present design being that large transverse borings in the piston used for admission and exhaust ports and which almost invariably result in breakage are entirely eliminated;

.Withthisobject in view I have devised a tool a practical embodiment of which is shown in the accompanying drawings in which Figure 1 shows a side elevation of the tool. Fig. 2 shows a longitudinal sectiontaken on theline 22 of Fig. 1. c Fig. 3 hows a cross v section taken on the line 3-3 of Fig. 2 and Fig. 4 shows a similar section on the linev 4-4 of Fig. 2.

In the drawings the tool is shown as a rotating hammer drill comprising a cylinder 1, a back head and handle portion 2 and a front head 3 these parts bein held togethefi by longitudinal bolts 4 whic pass throng lugs 5 and 6 on the back and front heads respectively and are secured in place by nuts 7. The cylinder 1 consists of two portions, 11 rear portion or cylinder proper 8 oflarw diameter and a front portion 9 of consider Reciprocatin in the cylinder is a piston consisting of a head portion 10 of such a diameter as to fit in the large diameter portion 8 of the cylinder and an elongated shank portion 11 which closely fits the forward part 9 in the cylin' der. On the inner surface of the smaller diameter of the cylinder. portion 9 is an annular inlet port 12 to which air or vother fluid under pressure is supplied through an inlet opening 13. In the piston shank 11 near the piston head 10 is a depression 14 which is so placed and is of such a length that for a short portion of the piston stroke near the end of its forward travel, the inlet rt 12 is placed in communication with the orward end of the cylinder portion 8 thus admitting fluid under pressure to the fora ward part of this chamber'which constitutes the cylinder proper. A short distance forward of the inlet opening 13 is a second" an" 'nular port 15 surrounding the piston which communicates by a. passage 16 to the em itreme rear end of the. cylinder portion 8.

A second set of depressions 17 forward. of

the. depression 14 in the piston shank 11 serve to establish communication for ashort :periochnear the rearward end of the piston annu a1: port- 15 thus admitting fluidunder pressure to the rear end of the cylinder. urrhunding the large diameter portion 8 of the cylinder near its center is a shallow .annular depression 18 from which a single exhaust port 19 leads to the atmosphere.

As shown, the. tool'is provided with means to rotate the drill steel comprising a fluted rifle bar 20 engaging a fluted nut 21 in a bore 22 in the rear end of the piston. This rifle bar 20 is rotatably mounted in the back heal of the cylinder and is provided with the usual ratchet mechanism 23. The forward part of the piston is provided with straight flutes 24 which engage similar grooves in a rotatable chuck 25 and through which slides drill steel 26. The drill steel isprovided with a bore 27 air' being provided to blow out the hole through a bore 28 in the piston.

In operation, supposing the parts to be in the position shown in Fig. 2 fluid under pressure will enter through the inlet open ing 13' and will pass through the annular port 12, past the shank depressions L7, annular port 15 and passage 16 to the rear end of the cylinder driving the piston forward. As soon as the rear ends of the depressions 17 pass the annular port 12 the passage of fluid into thcback end of the cylinder will be cut off, air thus being provided only 'during a short portion of the forward stroke of the piston. The fluid in the forward endof the cylinder is exhausted for a short portion of the stroke through the exhaust outlet 19. The depression 14 is so placed that the ingress of fluid to the vforward end of the cylinder will be very quickly cut oil so that stroll. between the annular port 12 and the e e sly, by the recoil of the piston ion of the small amount of a pistonrwliose strength. is not im y ti: v erse supply. ports which has shown to be very detrimental strengthnnd lasting qualities of the 2 to be understood that the present shot and deseription discloses only one specined modification of my invention-and other forms and modifications are included the spirit and scope of the invention. as expressed in the claims.

\ What I claim is:

1, line valveless peroussive tool, a cylinhaving a front portion. of small dian1eand rear portion of larger diameter, on having a head fitting said large porand a shanir fitt ng said small portion, ngle lire fluid inlet opening into said. 'ialler portion. a depression in said piston 3; said fluid inlet and the ward end oi cylinder portion gear the front end oi the piston stroke,

movement oi. the piston will ojylinder' by the depressions al'lows the.

passage leading from said cylinder at a point forward of said inlet opening to the rear end of said large cylinder portion, a depression inst piston shank for conneet- .ing said passage and said inlet opening. only 1 near the rear end of the piston stroke, and

means for exhausting the cylinder. I

2. In a valveless percussive tool a cylinder having a front portion of small diameter and a rear portion of larger diameter, a piston having a head fitting said large portion and a shank fitting said small portion, a'single live fluid inlet, said inlet opening into an annular port surrounding said smaller cylinder portion, a depression in said piston shank for connecting said fluid inlet and the forward end of said large cylinder portion only near the front end of the piston stroke, a passage leading from said cylinder at a point forward of said inlet opening to the rear end of said large cylinder portion, a depression in said pistonshank for commenting; said passage and said inlet opening only near the rear end of the piston stroke, and exhaust port near the center of the large cylinder portion.

In testimony whereof, I have hereunto set my hand.

LEWIS UONDICT BAYLES. Witnesses:

C. Q. When, G. S. lillinnr. 

